Temperature in the roof space was 15.38^oC at 11:46:43 p.m. today. Click here to see the temperature graph for today

1. Hook all the ducting together
2. Add some stiffening where collar tie's and framing was removed
3. Run the wire for the HP controller
4. Connect the HP air return duct
5. Add motorised damper to the HP return leg to stop short cycling
6. Add summer bypass motorised damper to HRV

1. Finding someone who knows how to install a HRV is easy, finding someone who knows how to install a ducted heat pump is harder but not impossible. Finding someone who knows about hooking a HRV up with a HP, like finding gold in a coal mine.
2. Don't buy your takeoffs until you have all your diffusers in. My ducting layout plans have changed about four times during the install due to roof space layout. Now I've got a whole bunch of unneeded takeoffs (soon to be on TradeMe) and I still don't have all the takeoffs I need.
3. Over estimate the amount of ducting you will need. I think I used twice what I originally thought
4. The roof space is hot and yucky, plan to install during the winter or early in the morning and at night. Even in August, on a nice day it is unbearably hot in the roof space during the day.
5. For every hour I've spent actually installing the units I've spent 2 running around for bits and pieces or researching. Always going to be harder the first time!
6. Don't underestimate how much space the ducting will take up in the ceiling and remember to leave a crawl space through it

Too hot up in the ceiling to do anything over summer, but now winter is upon us so I really need to get this finished.
The Heat Pump guy turned up last week and hooked up the compressor to the air handler and we fired up the unit for a test, all seems to go ok.
I've also got the motorised dampers for the return leg and the summer bypass, I need to fit these and hook up the ducting and hopefully..... warmth
Time spent : 30 hours

Slow, slow progress. Finally have the HRV unit running, but not fully ducted in. Had to get both of the HP plenum's reworked as nether would fit around the ceiling framing. The return plenum is in place, going to try the supply one today. Most of the ducting is hooked up, once the HP supply plenum is fitted, I'll be able to hook up the rest. Condensate drain all but finished, just need to add a short flexible bit from the end of the pressure pipe to the HP air handler.
Time spent : 59 hours

Completed the hangers for the air handler and starting wiring together the temperature sensors. I added a 5th sensor to measure the roof space temperature to see if there was any merit in taking some heat from there. The roof space temperature should be displayed at the top of this page. Having the temperature sensor up there also lets me know if its going to be too hot to go up!
Time spent : 5 hours

Connected up some more ducting, and started on the hangers for the air handler. Went to the tip shop for some box section tube and made up a couple of hangers but then cocked up when drilling the holes for the threaded rod (hand drill and I skewed the holes). Have asked my buddy Gus to make them for me for me. (he has a drill press).

I've discovered how motorised dampers work too, thanks to Smooth-Air in Christchurch. The damper has 240v AC applied to the motor with a standard 2C + E cable and then there is another control wire, when line power is connected to this wire the motor operates the damper, when this control line is left open, the damper closes (or the other way around!)
Time spent : 4 hours

Starting to fit the ducting together, I'm going to need to buy more. I think I'm up to two times my original estimate.
I ran the wire for the HRV temperature monitoring system done to the computer. The DS18S20 sensors arrived today (ordered for RS components) but the 1-wire to USB converter is coming for the states so I'm expecting that will take a week or so to get here.
Time spent : 2 hours

Been a while since I updated this. I've decide to complicate the installation by adding a ducted heatpump into the mix. Getting this into the ceiling cavity made getting the HRV in place look like a walk in the park. There are also a whole bunch of questions that are still unanswered, there is not guarantee the HRV fans will push the air through the HP when the HP is turned off. I'll need to add a powered damper to the return leg of the HP to close off when the HP is not going to stop the HRV air from short cycling through this leg. No one seems to know how to power the damper motor from the HP controller.
The heatpump and plenums are in place in the ceiling, but not assembled or hung from the rafters. Hanging the unit has caused me some head scratching, but I think I have a plan now. There isn't much room to move and the unit needs to be hung in just the right place between the rafters. I'm going to build so hangers from threaded rod and box section steel tube so I can have some fine adjustment once its up.

The CleanAire HRV has no temperature sensors and the most basic control panel so it's going to be impossible to see want the temperatures are at the heat exchanger and how well the heat exchanger is working. I've decided to add four temperature sensors to the HRV unit using the DS18S20 1-wire sensor. I've got 4 of these on order and the plan is to put one in each spigot of the HRV and wire back to a PC for data logging.  I should be able to plot the different temperatures and see if this 90% efficiency is real or not. 
Time spent : 50 hours

Apparently one of the diffusers I put in the living room was "an eyesore" so I had to move it to another location a couple of meters away. Now I have a 280mm hole in the ceiling to patch. I glued a square of gib over the hole, will glue the cut out bit back in next week and plaster over. Started to run the ducting and put in the takeoffs and whatnot. Once all the ducting is in place there will but hardly any room to crawl around in the ceiling!
Time spent : 3 hours

Four diffusers in today. I found that the two others I had planned to install I just cant get to because of the roofline, so I'm all done with cutting holes in the ceiling and making a h-u-g-e mess (I hope). Time to start connecting everything together. 
Time spent : 2 hours

Got 1 more diffuser in, the rest of the ducting has arrived so no excused. These last ones are in the really hard to get at places. They are going to take some crawling to. Had some really heavy rain, No leaks around the exhaust vent, yahhoooo!
Time spent : 2 hours

Friday August 21th

Got 3 more diffusers fitted, that's 10 of them fitted now. I've run out of ducting and duct tape. Seems I have underestimated the lengths required. Need to order another 5 6 metre lengths.
Time spent : 3 hours

Got 2 more diffusers fitted, that's 7 of them fitted, 10 to go. Makes a hell of a mess cutting the holes in the ceiling. I brought a big hole saw that attaches to a drill, its fast and reasonably neat but makes such a mess. I saw a pretty neat looking hole cutter when I went into Holyoakes in Tawa to get a duct reducer. It uses a drill bit type cutter on a arm. I think that would make much less mess and be easier to use. It was $80, about $40 more than the hole cutter I'm using, but I think it would have been worth the money. too late for that here though!
Time spent : 3 hours

Started fitting the supply and exhaust diffusers. Got 5 of them fitted, would be a much easier job with more than one person. Need to mark the approximate position from below, measure this from a couple of points then climb up into the ceiling to see where this is in relation to the joists, drill a pilot hole, get back out of the ceiling, check the position, repeat until its right. Cutting the hole and connecting the ducting is the easy part!
Have also discovered that my initial working plans for the duct runs isn't going to work everywhere as the roof line wont allow some of  the runs, they can be moved but it means I'll need to get some extra ducting and takeoffs.
Time spent : 5 hours

Levelled up and braced the exhaust vent and ducted to the HRV. Fitting the supply vent by comparison was simple, bored a hole thru the soffit, connected the ducting, all done in about an hour. Hardest part was cutting the 282mm hole thru the asbestos soffit lining. That stuff is hard, tried not to breath too much of it in.  Going to rain tomorrow, will see if I installed the dektite flashing correctly.
Time spent : 3.5 hours

Monday August 10th

Started on the exhaust and inlet vents, there is no room in the soffits for vents except at the gable end so I'm fitting the inlet vent here. It's a standard diffuser type. I cant fit the exhaust vent there too as it will be too close to the inlet so I'm going through the roof and using a madonna cowl. For the "through the roof" vent I needed to cut a oval hole through the corrugated iron, using some old school tech drawing skills I projected the 250mm (diameter of the vent) onto a 20 degrees angle (slope of my roof) and got about 266mm's. I used Visio to draw a oval and printed out a template, the cut the hole using a jigsaw. The dektite flashing is riveted down and gobs of silicone applied, hopefully there wont be any leaks.
Time spent : 3.0 hours

Monday August 3rd

Been a while since any progress was made. I've been waiting for the next shipment of bits to arrive - all the vents and takeoffs etc. They got here on Friday so I'll be back in to it this week.

Installing the condensate drain has been a major pain in the arse. Nothing to do with the CleanAire system, I chucked out the ugly thinwall black plastic pipe they provided and ran the drain in 20mm pressure pipe. Finished the pressure pipe with a threaded end and then fashioned a short flexible run from the elbow supplied, a piece of washing machine hose and a threaded socket from a irrigation system that was lying about in the shed. Most of the effort was due to the very narrow access at the soffit, lots of forcing my body into very small places. Pleased that is over. Lost an PVC elbow, 40mm hole saw and a really cool magnet I'd had since I was a kid into the soffit space during the install. I really want them back but short of smashing out the soffit lining I cant see how.
Time spent : 10.0 hours

Have had the electric supply hooked up and so the unit has power. On the "low" speed setting I can barely hear the fans, on medium and high they make a bit of noise but there is no ducting on yet. There was a stud in the way of the ducting at the rear of the unit where the rubbish bin air filter will sit. I needed to cut that out and frame around it with 100x50's.
I'm surprised how simple the unit is (given the cost), two big rotary fans, a few resistors to control the fan speed and the aluminium heat exchanger core, I guess on the positive side, there is not a lot to go wrong! 
Time spent : 3.0 hours

Completed the rubbish bin air filter. I used a 75l bin from Bunnings, it was around $15. It's the "Homeware" brand. The plastic on this is quite brittle. A trip to Mega10 shows they have a similar sized bin made from more "rubbery" plastic, it was about $24. I think that may have been a better choice. I'm not going to rework this one though unless it fails on me.
Looking at the condensate drain, the supplied piping is some of the crappy black plastic tubing you get for home irrigation systems, I'm going to use something a little more robust, either 20mm conduit or pressure pipe. I've got some 20mm pressure pipe somewhere, so I'll see if I can find that. I'll need to fashion a flexible bit to go from the bottom of the HRV to the fixed pipe. Maybe some of the washing machine drain hose will do the job.
Time spent : 0.5 hours

Blocked off the summer bypass spigot with some insulated foil and duct tape. Got one spigot on the air filter, will get the other one on tomorrow. Hope to get some pics posted too. Fired the unit up using an extension cord, the fans blow rather than suck as in the documentation, hummmm, that's unexpected! The plans are drawn up incorrectly. Luckily I haven't purchased any of the duct splitters yet as these will change. The external fresh air inlet vent will need an adapter for it too, it was supplied as 250mm but the inlet hole is only 200mm.
Time spent : 1.5 hours

Finished running the wires, everything is in place now for the electrician to hook all the bits up. Getting the wires down the wall was a pain but using the kids connex magnetic connectors made thing a bit easier. Checked out the air filter, the parts are right, it's the drawing supplied that wrong. They have in inlet and outlet vents transposed. That may effect the ducting plans but only by a small amount.
Time spent : 2.0 hours

Didn't get much done tonight. I ran the controller wire down the wall. Looks like the air filter parts supplied are wrong, need to check tomorrow night.
Time spent : 1.0 hour

Back running the wires again, almost got them done. Fitted the power socket and ran the controller switch wires into the HRV. Just need to poke the wires down the all to the switch board and to the controller switch then I'll be ready for the electrician to come and hook everything up.
Time spent : 1.0 hour

Sunday May 24th

Ran the wires for the power and the controller. The controller is a mains voltage rotary 4 position switch. Would have been easier if this was a low voltage unit but I guess that would add complexity. I needed 5 cores to the switch so I ran a 1.5mm 2C + E and another 1.5mm 3C (Red, White & Blue). The controller will be in a cupboard, its not something that needs to be easy to access.
I also riveted the summer bypass spigot into place. Easy enough, only gotchca was one rivet had to be inserted from inside the unit behind the core, otherwise the rivet would have interfered with the core placement.  Luckily the guys at Avon had supplied the rivets and sealant and stuck instructions on one of the rivets.
Time spent : 2.0 hours

Back in the ceiling today. Hung the HRV from the rafters. Had to knock out one collar tie. I'll need to add something back later. Not enough room to use the turnbuckles on both sides. Just did one. Levelled everything up. Looks ok.
Time spent : 1.5 hours

Started on the air filter rubbish bin, cut the holes in each end. Going to need to get some bolts to hold the spigots on, pop rivets wont be long enough. Back in the ceiling dragged the HRV unit down to where its going to go. Not a lot of room to spare, had to lay the unit on its side in some places to get it through some bits. I hate the hold pink batts stuff, makes me itch and cough!
Time spent: 2 hours

Moved the HRV unit up into the ceiling, rope and pulley to start and then dragged it up the rest of the way. Got it up in the end (single handed). No damage to me, the unit, or the attic ladder so all good!
Time spent: 1 hour